Field of the Invention
The invention concerns a method to optimize a magnetic resonance sequence of a magnetic resonance apparatus, a method to operate a magnetic resonance apparatus, a sequence optimization unit, a magnetic resonance apparatus, and a non-transitory, computer-readable data storage medium encoded with programming instructions that, when the storage medium is loaded into a computer of a magnetic resonance apparatus, cause the magnetic resonance apparatus to execute such a method.
Description of the Prior Art
In a magnetic resonance apparatus (also called a magnetic resonance tomography system), the body of an examination subject (in particular a patient) that is to be examined is typically exposed to a relatively high basic magnetic field—for example of 1, 5, 3 or 7 Tesla—with the use of a basic field magnet. A magnetic field gradient is additionally applied by a gradient coil arrangement. Radio-frequency pulses (in particular excitation signals) are emitted via a radio-frequency antenna unit, which cause the nuclear spins of specific atoms in the patient to be excited to resonance by being flipped (deflected) relative to the magnetic field lines of the basic magnetic field. Upon relaxation of the nuclear spins, radio-frequency signals (known as magnetic resonance signals) are radiated, which are received by suitable radio-frequency antennas, and then processed further. The desired image data are reconstructed from the raw data acquired in such a manner.
For a defined measurement, a defined magnetic resonance sequence (also called a pulse sequence) is emitted that is composed of a series of radio-frequency pulses (in particular excitation pulses and refocusing pulses) as well as gradient switchings (gradient pulse activations) emitted in different spatial directions in coordination with the RF pulses. Readout windows must be set to match these pulses chronologically, these readout windows predetermining the time periods in which the induced magnetic resonance signals are received. In particular the time arrangement (the timing) within the magnetic resonance sequence—i.e. at which time intervals and/or in which chronological order which radio-frequency pulses and/or gradient switchings follow one another—is significant to the imaging.